SHIPPINGPORT, Pa. - Start-up procedures resumed Tuesday afternoon for Unit 2 at the Beaver Valley Power Station after an "unusual event" was noted earlier by company officials and the Nuclear Regulatory Commission.

Unit 2 was shut down Oct. 12 for refueling and maintenance work and was not fully operational when the unusual event occurred, according to Todd Schneider, media representative for FirstEnergy, owner of the Beaver Valley Power Station.

"We were restarting systems and bringing the plant back into service when some water transferred from the reactor coolant system into a hold tank," Schneider said.

According to an initial report from the NRC, the transfer, or leakage, from the reactor coolant system into the pressurized relief tank was greater than a 25 gallons-per-minute rate limit resulting in the declaration of an "unusual event" which is the lowest of four NRC emergency classifications.

Schneider said the problem occurred at approximately 3:05 a.m. Tuesday, and the "unusual event" declaration was over at 4:04 a.m.

"There was no release of radiation, and the public and our employees were never in any danger," Schneider noted.

The water inadvertently removed from the reactor coolant system is, indeed, radioactive, but ended up being routed to a holding tank also inside the plant's containment building.

According to the NRC, the duration of relief valve lifting was about nine minutes. The pressurized relief tank remained intact, and all other systems functioned as designed.

Schneider said plant personnel isolated the water line to stop the improper flow of reactor coolant water.

"At this point, we are going to review the start-up procedures, and we're going to look back to make sure those procedures accurately reflect the steps needed during a re-start," Schneider said.

He said it was not a case of human error but "more related to the start-up procedures that were underway."

There was no release of any radiation, and proper reactor water levels were maintained throughout the process.

According to Neil Sheehan with the NRC Public Affairs Office, the NRC's senior resident inspector reported to the site to monitor the company's handling of the event and any follow-up actions.

(McElwain can be contacted at mmcelwain@reviewonline.com)